I have seen some old time fiddlers play with the fiddle placed against their chest and cradled in the left arm, allowing them to call dances or to sing. I asked an old-timer about that style of playing, which he was using. He told me that he got tired of having a pain in the neck from playing in the traditional fashion, so he switched some years back. He'd been at it long enough that he had perfected his style to an art. That prompted me to go home and try it. What I discovered was that cradling the fiddle thus reduces the mobility of the left hand because you are holding the insrument with it, and I discovered that it also totally changed the dynamic of bowing. The tonal quality suffered such that I said, "Aw, to hell with it," and went back to the traditional under the chin stance.
I've also seen a lot of fiddlers not bother with a shoulder rest which in my humble opinion is a mistake too. Without the shoulder rest, you wind up holding the fiddle up with the left hand, which reduces the dexterity with which you can finger the notes.